Daytime versus out-of-hours surgery for Chronic Subdural Hematoma.

Chronic Subdural Hematoma (CSDH) is one of the most common neurosurgical pathologies. Due to an elderly demographic with increasing co-morbidities, surgery is often deferred out of hours. This may reduce complication risk, but increases length of stay and may compromise patient care due to delayed surgery. We performed a retrospective service evaluation of CSDH patients undergoing primary surgery (September 2021-September 2023) at a tertiary neurosciences centre. Out of hours (OOH) was defined as an operation start time outside 8 am-8 pm. Primary outcome was recurrence requiring repeat surgery. Secondary outcomes included complications, thromboembolic events (DVT/PE), length of stay, and in hospital mortality. Differences were assessed using Chi-Squared tests and Student's t-tests. A total of 263 patients were included (200 (76.0 %) male, mean age 75.0 ± 11.3 yrs). Median time from admission to surgery was 37 h (IQR 14-71.5 h). In total, 49.8 % (131/263) of operations took place OOH. There were no significant differences in baseline characteristics between the two groups. At a median follow-up of 9.2 months (IQR 4.8-13.2 months) there was no difference in recurrence rates between OOH and in hours groups (14.5 % vs. 17.7 %, p = 0.483). There was no difference in complication rates (13.7 % vs 16.2 %, p = 0.585), thromboembolic events (3.8 % vs 3.1 %, p = 0.743), length of stay (mean 15.9 vs 15.2 days, p = 0.787), or in-hospital mortality (2.3 % vs 3.1 %, p = 0.483). OOH surgery for CSDH surgery is safe, does not appear to affect complications, recurrence, or mortality, and should be considered in appropriately selected cases.